If you’ve been in some of the Sheriff’s vehicles lately, you may have noticed a new radio has been installed: the Motorola APX 7500 O5. The change is part of an upgrade to allow the use of additional frequencies and functions. Using this radio is essentially unchanged from any other vehicle radio: turn it on, select the channel, and press the PTT button on the microphone. But how you do this is slightly different.
The biggest visible change is the orange screen that displays the channel along with other information. The layout of the knobs and buttons can be seen on the radio’s Quick Reference Card, available in the Documents section of the SAR website. The three most important controls—power (on/off), volume, and channels—are shown in the photo above. Rotate the channel knob through the 16 Zone-1 channels until you find Tac 4 (see channel list sidebar). The radio also has many advanced capabilities beyond the basic send-and-receive functionality, including secured communications, telephone capabilities, and other features that won’t be used by SAR.
In addition to new radios being put in, the power on/off function in the vehicles is being changed. In the past, the power to the radio was sometimes wired through the ignition switch. In that situation the ignition needs to be on in order to operate the radio. The alternative was to have the radio wired directly to the battery … which then drained the battery if the vehicle was parked and the radio was not specifically turned off. Now all vehicles are standardized so the ignition must be on for the radio to work; the radio will automatically lose power when the key is turned off.
An additional change: All accessories will automatically be powered off by a ‘power tamer’ within 30 to 60 minutes after the ignition switch is turned off. This should help minimize the chance of having a dead battery due to accessories (such as a GPS charger) consuming battery power when the engine is of